Actually, Dan said he’d been writing down his brother’s dreams for 7 years. You’re only thinking it’s age 8 cause that happened to be the book that Alex picked up from his brother’s belongings. However, since he stopped dreaming at 12 and it’s been 8 years, he’s currently 20, and Alex started going to Dreamland (and Dan started writing them down, probably in childspeak, I assume) at age 5.

I’ve got the answer. Alex just needs to make like Freddy Krueger, kill some kids in their dreams, and then check the obituaries in the newspaper when awake. Best spell out a message with the first letters of their names for added proof. =D